Problem: $\dfrac{3}{4} + \dfrac{6}{12} = {?}$
Answer: $ = {\dfrac{3 \times 3}{4 \times 3}} + {\dfrac{6 \times 1}{12 \times 1}} $ $ = {\dfrac{9}{12}} + {\dfrac{6}{12}} $ $ = \dfrac{{9} + {6}}{12} $ $ = \dfrac{15}{12}$